0 QTRS
p(0) → s(s(0)) p(s(x)) → x p(p(s(x))) → p(x) le(p(s(x)), x) → le(x, x) le(0, y) → true le(s(x), 0) → false le(s(x), s(y)) → le(x, y) minus(x, y) → if(le(x, y), x, y) if(true, x, y) → 0 if(false, x, y) → s(minus(p(x), y))